package com.pcy.project.request;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Map;
import java.util.Set;

/**
 * @author: 清秋
 * @email:
 * @datetime: 14:18 2021/12/7
 * @Description: 该类用于封装提供网络请求的功能代码，用于发去网络请求，并将网络的数据进行返回
 */
public class HttpUtils {
    /**
     * 该函数用语实现get请求的结果进行返回
     *
     * @param path 请求的资源路径
     * @return 请求的结果
     */
    public static String get(String path) {
        String line = "";//最开始空行
        String result = "";//每次读取到以后，都要累计起来的读取结果

        BufferedReader reader = null;
        InputStreamReader inputStreamReader = null;
        InputStream inputStream = null;

        try {
            //Union Resource Location (URL) 统一资源定位
            URL url = new URL( path );
            URLConnection connection = url.openConnection();
            //进行连接
            connection.connect();

            inputStream = connection.getInputStream();

            //字符流：可以按行读

            //将字节输入流转换成字节读取流
            inputStreamReader = new InputStreamReader( inputStream );
            reader = new BufferedReader( inputStreamReader );

            while ((line = reader.readLine()) != null) {
                result += line;
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //关闭读取流
            try {
                //先开的后关，后开的先关
                if (reader != null) {
                    reader.close();
                }
                if (inputStreamReader != null) {
                    inputStreamReader.close();
                }
                if (inputStream != null) {
                    inputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }

    /**
     * java原生代码实现post请求，并返回请求结果
     *
     * @param path   请求的路径
     * @param header 请求头信息
     * @param data   请求数据
     * @return 请求的结果
     */
    public static String post(String path, Map<String, String> header, byte[] data) {

        OutputStream outputStream = null;
        BufferedReader reader = null;
        InputStream inputStream = null;

        String result = "";

        try {
            URL url = new URL( path );
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod( "POST" );
            conn.setDoInput( true );
            conn.setDoOutput( true );

            //请求头设置
            //ContentType:application/json
            //Authorization:"Basic"+"xxx"
            //如何拿到所有map中的数据(如何获取map数据)
            //List:有序，可以使用for循环遍历
            //Set：无序，增强for循环，迭代器
            //Map：无序，get(Key)=>keySet()=>增强for循环遍历key

            if (!header.isEmpty()) {
                Set<String> keys = header.keySet();
                for (String key : keys) {
                    String value = header.get( key );
                    conn.setRequestProperty( key, value );
                }
            }
            conn.connect();  //连接

            //将请求数据发送出去
            outputStream = conn.getOutputStream();
            outputStream.write( data ); //把请求的数据发送出去

            //读取响应的数据
            inputStream = conn.getInputStream();
            reader = new BufferedReader( new InputStreamReader( inputStream ) );
            String line = null;
            while ((line = reader.readLine()) != null) {
                result += line;
            }


        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (inputStream != null) {
                    inputStream.close();
                }
                if (reader != null) {
                    reader.close();
                }
                if (outputStream != null) {
                    outputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }
}
